1. Technical Field
The present invention relates to a liquid ejection head and a liquid ejection device provided with piezoelectric elements having electrodes and a piezoelectric layer of a piezoelectric material, and adapted to expel droplets of liquid from nozzle openings.
2. Related Art
One known structure for a piezoelectric element has a piezoelectric layer of a piezoelectric material that exhibits an electrical-mechanical conversion function, for example, a crystallized dielectric material, sandwiched by two electrodes. Piezoelectric elements of this kind may be installed in a liquid ejection head to serve as actuator devices that oscillate in flexural oscillation mode, for example. One typical example of a liquid ejection head, for example, is an inkjet recording head that includes oscillator plates which partially define pressure generation chambers communicating with nozzle openings for expelling ink droplets, the head being adapted to pressurize the ink of the pressure generation chambers through deformation of the oscillator plates by piezoelectric elements in order to expel ink droplets from the nozzle openings. The piezoelectric elements installed in such an inkjet head are produced, for example, by forming a uniform piezoelectric material layer over the entire surface of the oscillator plate by deposition technique, and etching away the piezoelectric material layer by a lithography process into shapes that correspond to the pressure generation chambers, to form an independent piezoelectric element for each of the pressure generation chambers.
An example of a piezoelectric material used in such piezoelectric elements is lead zirconate titanate (PZT) (see Japanese Laid-Open Patent Application Publication No. 2001-223404).